Image forming apparatus

ABSTRACT

An image forming apparatus includes: an image forming portion capable of forming an image on a recording medium; an operation portion for performing an operation of the image forming apparatus; a push button which is arranged in a surface of the operation portion, and with which a signal of stopping an image forming action performed by the image forming portion is input; a receiving portion provided in the operation portion so as to be able to receive a radio signal from a communication component by placing the communication component transmitting the radio signal so as to face the receiving portion; and at least a central portion of the push button located at a position recessed from the surface of the operation portion.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an image forming apparatus such as aprinter, facsimile machine, or copier.

Description of the Related Art

An image forming apparatus which forms an image such as a character, apicture, or a photograph on a recording medium is widely used. In asurface of an operation portion of the image forming apparatus, there isarranged a push button for use in inputting a signal for stopping (orstarting) an image forming action.

In the image forming apparatus, there has been developed a technique ofinputting print data by using near field communication. Japanese PatentApplication Laid-Open No. 2014-157532 discloses a printing system whichforms an image by inputting print data into an image forming apparatusby using near field communication from an electronic camera, a mobilephone terminal, a tablet personal computer or the like.

In the case of inputting print data into an image forming apparatus byusing near field communication, a user needs to be authenticated by theimage forming apparatus while holding an equipment body, from which theprint data is to be transmitted, or an authentication medium such as anIC card close to a receiving portion of the image forming apparatus. Asdisclosed in Japanese Patent Application Laid-Open No. 2014-157532, thereceiving portion is arranged in an operation portion where a pushbutton related to the start or stop of an image forming action isprovided.

Therefore, when bringing the equipment body or the authentication mediumclose to the receiving portion, the user might push the push buttonrelated to the start or stop of an image forming action by mistake,which leads to an input of an instruction related to the start or stopof the image forming action unfavorably.

SUMMARY OF THE INVENTION

Therefore, it is an object of the present invention to provide an imageforming apparatus capable of reducing opportunities of pushing a pushbutton related to the start or stop of an image forming action even inthe case of bringing a communication component close to an operationportion when performing near field communication.

According to an aspect of the present invention, there is provided animage forming apparatus including: an image forming portion capable offorming an image on a recording medium; an operation portion forperforming an operation of the image forming apparatus; a push buttonwhich is arranged in a surface of the operation portion, and with whicha signal of stopping an image forming action performed by the imageforming portion is input; a receiving portion provided in the operationportion so as to be able to receive a radio signal from a communicationcomponent by placing the communication component transmitting the radiosignal so as to face the receiving portion; and at least a centralportion of the push button located at a position recessed from thesurface of the operation portion.

According to another aspect of the present invention, there is providedan image forming apparatus including: an image forming portion capableof forming an image on a recording medium; an operation portion forperforming an operation of the image forming apparatus; a push buttonwhich is arranged in a surface of the operation portion, and with whicha signal of starting an image forming action performed by the imageforming portion is input; a receiving portion provided in the operationportion so as to be able to receive a radio signal from a communicationcomponent by placing the communication component transmitting the radiosignal so as to face the receiving portion; and at least a centralportion of the push button located at a position recessed from thesurface of the operation portion.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory diagram illustrating a configuration of animage forming apparatus according to a first embodiment.

FIG. 2 is a perspective view illustrating an appearance of the imageforming apparatus.

FIG. 3 is an explanatory diagram illustrating an authenticationoperation using an authentication medium.

FIG. 4 is an explanatory diagram illustrating a key arrangement in aninput operation portion.

FIG. 5 is an explanatory diagram illustrating an antenna arrangement ina vertical section of the input operation portion.

FIG. 6 is a block diagram illustrating a control system of the imageforming apparatus.

FIG. 7 is a flowchart of authentication control.

FIG. 8 is a sectional view of an input operation portion according tothe first embodiment.

FIG. 9 is a sectional view of an input operation portion according to asecond embodiment.

FIG. 10 is a top view of an input operation portion according to a thirdembodiment.

FIG. 11 is an explanatory diagram illustrating another structure of akey switch.

DESCRIPTION OF THE EMBODIMENTS

Embodiments of the present invention will now be described in detail inaccordance with the drawings.

First Embodiment (Image Forming Apparatus)

FIG. 1 is an explanatory diagram illustrating a configuration of animage forming apparatus according to a first embodiment. As illustratedin FIG. 1, an image forming apparatus 100 is an intermediate transfertype full-color laser beam printer which forms an image by anelectrophotographic system.

Image forming portions 1Y, 1M, 1C, and 1K, which are examples of animage forming portion, an intermediate transfer belt 18, a secondarytransfer outer roller 24, and a fixing device 30 are able to form animage on a recording medium. The image forming portion 1Y forms a yellowtoner image on a photosensitive drum 11 and transfers the toner imageonto the intermediate transfer belt 18. The image forming portion 1Mforms a magenta toner image on the photosensitive drum 11 and transfersthe toner image onto the intermediate transfer belt 18. The imageforming portions 1C and 1K form a cyan toner image and a black tonerimage on the photosensitive drum 11, respectively, and transfer therespective toner images onto the intermediate transfer belt 18.

The four-color toner images transferred to the intermediate transferbelt 18 are conveyed to a secondary transfer part T2 and thentransferred to a sheet S. A cassette 40 accommodates stacked sheets. Afeed roller 22 separates the top sheet S and feeds the sheet S into aregistration roller 23. The registration roller 23 corrects the skew ofthe sheet and feeds the sheet to the secondary transfer part T2 whilematching the timing with the toner images on the intermediate transferbelt 18.

The secondary transfer outer roller 24 is brought into contact with theintermediate transfer belt 18 on the secondary transfer inner roller 25to form the secondary transfer part T2. A DC voltage is applied to thesecondary transfer outer roller 24, by which the toner images carried onthe intermediate transfer belt 18 are transferred to the sheet S. Thesheet S to which the toner images are transferred is conveyed to thefixing device 30 and then heated and pressed so that the images arefixed to the sheet S. Thereafter, the sheet S is discharged to adischarge tray 51 by a discharge roller 33.

(Image Forming Portion)

The image forming portions 1Y, 1M, 1C, and 1K have substantially thesame configuration, though they are different from each other in thecolor of toner used in the developing device 14. Therefore, the imageforming portion 1Y will be described here and duplicate descriptionrelated to the image forming portions 1M, 1C, and 1K is omitted.

In the image forming portion 1Y, a charging roller 12, an exposuredevice 13, a developing device 14, a transfer roller 15, and a drumcleaning device 16 are arranged around the photosensitive drum 11.

In the photosensitive drum 11, a photosensitive layer is formed on thesurface of the base of a metal pipe. The charging roller 12 electricallycharges the photosensitive drum 11 to a uniform potential due toapplication of an oscillation voltage to the charging roller 12, wherethe oscillation voltage is generated by superposing an AC voltage on aDC voltage. The exposure device 13 forms an electrostatic latent imageon the photosensitive drum 11 by scanning the photosensitive layer witha laser beam to expose the photosensitive layer.

The developing device 14 develops the electrostatic latent image on thephotosensitive drum 11 to toner images by using a two-componentdeveloper. Upon application of a DC voltage to the transfer roller 15,the transfer roller 15 transfers the toner images carried on thephotosensitive drum 11 to the intermediate transfer belt 18. The drumcleaning device 16 frictionally slides the cleaning blade on thephotosensitive drum 11 to collect transfer residual toner on thephotosensitive drum 11.

(Arrangement of Operation Portion)

FIG. 2 is a perspective view illustrating an appearance of the imageforming apparatus. As illustrated in FIG. 2, the image forming apparatus100 includes the cassette 40 for accommodating sheets in the lower part.In the upper part of the image forming apparatus 100, the image formingapparatus 100 includes the discharge tray 51 for stacking sheets onwhich the images are formed.

An operation portion 61 is provided beside the discharge tray 51 on theupper surface of the image forming apparatus 100. In the operationportion 61, an input operation portion 63 for performing various inputsis arranged on the near side of a liquid crystal screen 62 a forperforming various displays. The liquid crystal screen 62 a displays thestate of the power supply of the image forming apparatus 100, thepresence/absence of a job, an error condition or the like.

On the surface of the liquid crystal screen 62 a, a transparent touchpanel 62 b is provided. The setting contents such as the number ofprocessed sheets, the kind of sheet, temperature, humidity, and the likedisplayed on the liquid crystal screen 62 a are able to be changed by atouch panel 62 b through icons displayed on the liquid crystal screen 62a.

Through the liquid crystal screen 62 a where the touch panel 62 b isprovided, operations and settings for a printer are able to be performedsuch as network settings, job deletion, or various settings.

(Authentication through Near Field Communication)

FIG. 3 is an explanatory diagram illustrating an authenticationoperation performed with a mobile terminal brought close to the inputoperation portion. As illustrated in FIG. 3, the image forming apparatus100 is able to perform wireless communication through near fieldcommunication (NFC) between a mobile terminal (communication component)301 and an antenna 261 b. The mobile terminal 301 receives an imageforming job including image data and various types of setting datathrough near field communication. The image forming apparatus 100 isable to perform remote control through near field communication by usingthe mobile terminal 301.

The image forming apparatus 100 has an authentication function usingnear field communication so as to be able to identify an individual fromthe viewpoint of security to simplify the operation so that theoperation can be conveniently performed.

In the near field communication, the communication distance is limitedto 10 cm or so and therefore the authentication of the mobile terminal301 is performed with the mobile terminal 301 “held over” the inputoperation portion 63. After the authentication, data transfer of theimage forming job is performed from the mobile terminal 301 to the imageforming apparatus 100. The data of the image forming job is data for oneprinting unit, and includes data of one or more images, printingcondition specification data, and a print command.

(Input Operation Portion)

FIG. 4 is an explanatory diagram illustrating a key arrangement in theinput operation portion. FIG. 5 is an explanatory diagram illustratingan antenna arrangement in a vertical section of the input operationportion.

As illustrated in FIG. 4, an antenna portion 261 is arranged in a nearside position on a panel cover 63 c of the input operation portion 63.On the panel cover 63 c, a cross-shaped indicator 261 m is printed wherethe indicator 261 m serves as a marker when bringing the mobile terminal(301: FIG. 3) into close. In the input operation portion 63, theindicator 261 m is provided in a position where the mobile terminal 301is positioned to face the antenna portion 261 so that the antennaportion 261 is able to receive a radio signal.

As illustrated in FIG. 5, the antenna 261 b, which performs wirelesscommunication with the mobile terminal (301: FIG. 3), is placed justbeneath the indicator 261 m of the antenna portion 261. The antenna 261b is arranged under the panel cover 63 c. The antenna portion 261, whichis an example of a receiving portion, is provided in the input operationportion 63 so as to be able to receive a radio signal from the mobileterminal 301 by causing the mobile terminal 301, which is an example ofa component of transmitting the radio signal, to face the surface of theinput operation portion 63.

As illustrated in FIG. 4, LED lamps (211 to 214) for performing variousdisplays are laid out on the panel cover 63 c of the input operationportion 63. The data display portion 211 displays the action of a job orthe presence/absence of a job by turning on/off or blinking the LEDlamp. The wireless LAN display portion 212 displays a state of thewireless LAN by blinking the LED lamp. The error display portion 213indicates an error by turning on the LED lamp. The power display portion214 displays the ON/OFF state of the power supply by turning on/off theLED lamp.

(Setting Key and Execution Key)

As illustrated in FIG. 4, the input operation portion 63, which is anexample of an operation portion, is provided for a user to performoperations of the image forming apparatus 100. On the panel cover 63 cof the input operation portion 63, there are laid out setting keys 63 a(241 to 243) related to setting input and screen operations and anexecution key 63 b (an image formation start button 251) for starting anaction of the image forming apparatus 100.

(1) A home key 221 is pressed to return the display of the liquidcrystal screen 62 a to the home screen.

(2) A reset key 222 is pressed to reset the set contents displayed onthe liquid crystal screen 62 a to default values.

(3) A back key 223 is pressed to return the display of the liquidcrystal screen 62 a to the screen which is one level upper in thehierarchy.

(4) A power saving key 225 is pressed to shift to a power saving modeand is pressed again to recover from the power saving mode.

(5) A status confirmation key 226 is pressed to display a print statusand a report output status on the liquid crystal screen 62 a forconfirmation.

(6) Any key of the numeric keypad 231 is pressed to input a numeral, asymbol, or a character in a cursor position displayed on the liquidcrystal screen 62 a. The key of the numeric keypad 231, which is anexample of a second push button, is a button for inputting a numericalvalue and therefore is provided to input a signal for an operation otherthan the stop and start of the image forming action.

(7) An authentication key 241 is pressed to cause the display of theliquid crystal screen 62 a to enter a password mode for inputting apassword number or to exit the password mode.

(8) A clear key 242 is pressed to clear the numeral or character in thecursor position.

(9) A counter key 243 is pressed to display counter information, whichcontains a record of how many sheets the image forming apparatus 100printed, on the liquid crystal screen 62 a.

(10) When settings are made on the liquid crystal screen 62 a, a virtualsetting key, not illustrated, is displayed on the liquid crystal screen62 a. Pressing the virtual setting key with a finger activates the touchpanel 62 b to generate a required input signal.

(11) When manual start is performed on the liquid crystal screen 62 a, avirtual start key, not illustrated, is displayed on the liquid crystalscreen 62 a. Pressing the virtual start key with a finger activates thetouch panel 62 b to start the image formation.

(12) A stop key 251 aborts a job and stops the printing action of theimage forming apparatus 100. The stop key 251, which is an example of afirst push button, is arranged in the surface of the input operationportion 63 and is provided to input a signal of stopping the imageforming action.

In an embodiment having a start key, the start key, which is an exampleof the first push button, is arranged in the surface of the inputoperation portion 63 and is provided to input a signal of starting theimage forming action.

(Authentication Circuit)

FIG. 6 is a block diagram illustrating a control system of the imageforming apparatus. As illustrated in FIG. 5, a tactile switch 266 ismounted on an operation board 265, where the tactile switch 266 is aswitching element for detecting the press of the setting key 63 a or theexecution key 63 b. On the operation board 265, an operation circuit 72for controlling the image forming apparatus 100 is mounted on the basisof manipulated inputs of the setting key 63 a and the execution key 63 bas illustrated in FIG. 6.

As illustrated in FIG. 6, an authentication circuit 71 is also mountedon the operation board 265, where the authentication circuit 71 performsauthentication by receiving ratio waves of near field communicationoutput from the mobile terminal 301 (FIG. 3) by using the antenna 261 b.The antenna 261 b is connected to the operation board 265 via aconnector 262.

As illustrated in FIG. 6, the liquid crystal screen 62 a displays thestate of the settings of the image forming portions 1Y, 1M, 1C, and 1Kand the action state through the operation circuit 72. The operationcircuit 72 receives inputs from the touch panel 62 b, the setting key 63a, and the execution key 63 b.

A control portion 73 of the image forming apparatus 100 is able to beoperated through a personal computer 75 connected by a USB cable, awired LAN, or a wireless LAN or through the input operation portion 63provided in the image forming apparatus 100.

The control portion 73 receives an image forming job including imagedata by the wired LAN or wireless LAN from the personal computer 75. Thecontrol portion 73 receives an image forming job including image data bynear field communication from the mobile terminal 301. The controlportion 73 controls the image forming portions 1Y, 1M, 1C, and 1K toperform the image forming job thereof.

The control portion 73 performs an authentication action for confirmingthe authority to use the image forming apparatus 100 with the mobileterminal 301 prior to receiving the image forming job.

If the mobile terminal 301 is held close to the antenna 261 b asillustrated in FIG. 3, authentication data is stored in theauthentication circuit 71 through the antenna 261 b from the mobileterminal 301. If an authentication item of the stored authenticationdata matches an authentication item of the image forming apparatus 100,the authentication circuit 71 authenticates the mobile terminal 301 andtransmits an input permit signal to the operation circuit 72.

If the mobile terminal 301 is authenticated, various settings related toimage forming conditions are transmitted from the mobile terminal 301 tothe antenna 261 b and then the various settings are input to the controlportion 73 through the operation circuit 72, and are automatically set.This removes the burden of performing manual setting through theoperation portion 61.

Subsequently, the authentication circuit 71 transmits data of the imageforming job transmitted from the mobile terminal 301 to the operationcircuit 72 and then the operation circuit 72 forwards the data to thecontrol portion 73. The control portion 73 holds the data of the settingcontents and of the image forming job and then outputs action commandsto respective portions of the image forming apparatus 100.

(Arrangement of Stop Key)

As illustrated in FIG. 4, in the input operation portion 63, a keyswitch is arranged on the panel cover 63 c so that a user is able tooperate the input operation portion 63 fluently without confusion.

From the viewpoint of human engineering, it is natural and desirablethat a series of key operations are performed from the upper left to thelower right. Therefore, in the image forming apparatus 100, theexecution key 63 b, which is pressed after the various settings arecompleted, is arranged at the lower right of the input operation portion63. The stop key is for use in stopping the image forming action anddiffers from a power key for turning on or off the power supply.

(Arrangement of Antenna)

From the viewpoint of human engineering, the input operation portion 63and the antenna 261 b need to be arranged so as to be close to eachother in order to ensure that the user who holds the authenticationmedium is the same as the user who operates the input operation portion63. Although it is possible to provide the authentication circuit 71 ona board other than the operation board 265, it is preferable that thedistance between the authentication circuit 71 and the operation circuit72 is shorter. It is also preferable that the number of parts is less.Therefore, the antenna 261 b is disposed close to the operation board265.

For this reason, in the image forming apparatus 100, the antenna 261 bis arranged in the nearest position on the near side of the inputoperation portion 63 and the authentication circuit 71 is provided inthe vicinity of the operation circuit 72 on the operation board 265.Therefore, the antenna 261 b is provided close to the setting key 63 aand the execution key 63 b to transmit or receive a radio signal to orfrom the mobile terminal 301 held with fingers.

(Authentication Control)

FIG. 7 is a flowchart of authentication control. The image formingapparatus 100 has three lines of command for starting a printing action.

As illustrated in FIG. 6, the first line of command is in a case ofusing a USB cable, a wired LAN, or a wireless LAN. An image forming jobis transmitted from a personal computer 75 connected via the USB cable,the wired LAN, or the wireless LAN. Upon receiving the image forming jobfrom the personal computer 75 (S101), the control portion 73 activatesthe image forming portions 1Y, 1M, 1C, and 1K to start the printingaction (S105).

The second line of command is in a case of manually starting a copyprocess by performing various settings on the liquid crystal screen 62a. A user performs required settings by operating a setting key 63 a ofthe operation portion 61 and a virtual key displayed on the liquidcrystal screen 62 a (S102). Thereafter, the user presses a virtual startkey displayed on the liquid crystal screen 62 a with a finger (S103).Thereby, the control portion 73 activates the image forming portions 1Y,1M, 1C, and 1K to perform the printing action (S105).

The third line of command is in a case of transmitting an image formingjob such as photographic printing or the like from the mobile terminal(smartphone) 301. When the mobile terminal 301 is brought close to theoperation portion 61, the antenna 261 b and the authentication circuit71 automatically detect the mobile terminal 301 by near fieldcommunication, and thereby authentication of the authority to use theimage forming apparatus 100 is performed (S104).

If the authentication is completed successfully (YES in S104), thecontrol portion 73 causes the mobile terminal 301 to transmit settingdata and image forming job data and stores the setting data and imageforming job data to perform the printing action (S105).

Upon starting the printing action (S105), the control portion 73determines whether or not the stop key 251 is pressed (S106).

If the stop key 251 is pressed after starting the printing action, thecontrol portion 73 stops the printing action (S108). This function isprovided for the reason of avoiding unnecessary printing in the case ofmaking a mistake in the number of prints or the like.

If the printing action is completed (YES in S107) without pressing thestop key 251 (NO in S106), the control portion 73 stops the printingaction (S108).

(Key Misoperation During Authentication)

As illustrated in FIG. 3, when the user holds the mobile terminal 301with his/her fingers 311 for authentication, the user's thumb 311 a,forefinger not illustrated, middle finger 311 c, annular finger 311 d,and little finger 311 e are protruding from the mobile terminal 301toward the input operation portion 63 side.

The mobile terminal 301 is able to be authenticated by being broughtclose to the antenna portion 261 up to approx. 10 cm apart therefrom.Depending on the state of the antenna 261 b or on the performance of themobile terminal 301, however, the user might bring the mobile terminal301 closer to the antenna portion 261 in some cases. In an extreme case,the user might press the mobile terminal 301 against the input operationportion 63. In such a case, the mobile terminal 301 or any of the user'sfingers 311 is likely to touch or press a key of the numeric keypad 231or the stop key 251 by mistake.

In this case, the setting keys 63 a (221 to 243) do not immediatelyaffect the action of the image forming apparatus 100 even in the case ofmisoperation. The numeric keypad 231 includes the setting keys 63 awhich is only used to input the settings and do not immediately affectthe action of the image forming apparatus 100. Besides the numerickeypad 231, the home key 221, the reset key 222, the back key 223, thepower saving key 225, the status confirmation key 226, the keys of thenumeric keypad 231, the authentication key 241, the clear key 242, andthe counter key 243 are classified into the setting keys 63 a. If thepower saving key 225 is pressed during printing action, the inputthereof is validated after the completion of the printing action, bywhich the state of the image forming apparatus 100 is changed.Therefore, the power saving key 225 is classified into the setting key63 a.

The execution key 63 b (251) immediately affects the action of the imageforming apparatus 100 in the case of misoperation. Specifically, if thestop key 251 is erroneously operated, the image forming apparatus 100stops the reception of the print data and of the action command (job) orstops the image forming job under execution in the image formingapparatus 100 (YES in S106: FIG. 7). Moreover, depending on a programfor the image forming apparatus 100, an input of the execution key 63 bmay cause a display related to the image forming action on the displayportion in some cases, though not directly affecting the image formingaction immediately. Even in the case of not directly affecting the imageforming action, an action causing a new situation related to the imageforming action is not desirable for a user.

In the first embodiment, the height of the pressed surface is madedifferent between the setting key and the execution key. At least thecentral portion of the stop key 251 is located at a position recessedfrom the surface of the input operation portion 63. Similarly, in theembodiment having the start key, at least the central portion of thestart key is located at a position recessed from the surface of theinput operation portion 63.

(Height of Pressed Surface)

FIG. 8 is a sectional view of the input operation portion according tothe first embodiment. As illustrated in FIG. 8, each key of the numerickeypad 231 and the stop key 251 are biased against the operation panelcover 63 c with coil springs 68 arranged between each key of the numerickeypad 231 and the operation board 265 and between the stop key 251 andthe operation board 265. Therefore, each key of the numeric keypad 231and the stop key 251 are each held with a fixed gap from the tactileswitch 266 mounted on the operation board 265.

If any key of the numeric keypad 231 or the stop key 251 is presseddownward, the gap is closed and then the tactile switch 266 is pressed apredetermined distance. Thereby, the output of the tactile switch 266 isinverted and the input of the key of the numeric keypad 231 or the stopkey 251 is validated.

In the first embodiment, the pressed surface of any key of the numerickeypad 231 has an outer peripheral portion around the central portionthereof protruding more than the central portion in the oppositedirection to the pressing direction. The pressed surface of the stop key251 has an outer peripheral portion around the central portion thereofprotruding more than the central portion in the opposite direction tothe pressing direction. Also in this case, the outer peripheral portionof the pressed surface of the key of the numeric keypad 231 protrudesmore than the outer peripheral portion of the pressed surface of thestop key 251 in the opposite direction to the pressing direction, bywhich misoperation of the stop key 251 less easily occurs than the keysof the numeric keypad 231.

Any key of the numeric keypad 231 has a key height set so that thehighest convex portion 231 b protrudes more than the surface of theoperation panel cover 63 c. The key of the numeric keypad 231 can bepressed without being obstructed by the panel cover 63 c, and thereforeit is easy to validate the input of the key of the numeric keypad 231.On the other hand, the highest convex portion 251 b of the stop key 251is lower than the convex portion 231 b of the key of the numeric keypad231. This prevents the input of a key from being validated even if thestop key 251 is pressed by mistake with the mobile terminal 301 or anyof the user's fingers 311 when the user brings the mobile terminal 301close to the antenna portion 261.

Furthermore, the convex portion of the execution key 63 b (stop key 251)is substantially flush with or slightly lower than the surface of theoperation panel cover 63 c. Thereby, even if the user's fingers 311 comeclose to the stop key 251 for performing authentication by bringing themobile terminal 301 close to the antenna portion 261, any of the user'sfingers 311 abuts against the operation panel cover 63 c. Therefore, theinput of the execution key 63 b is not easily validated.

The user presses the center of the key when intentionally pressing thestop key 251, and therefore it is not difficult to validate the input ofthe stop key 251.

In the case where the setting key 63 a such as a key of the numerickeypad 231 is pressed by mistake, the key input is invalidated unlessthe input mode of the setting key 63 a has been entered operationally.Even if the input mode has been entered, the operation of the settingkey 63 a is validated only after pressing “a decision key displayed onthe liquid crystal screen 62 a” which is used to decide an input withthe input contents displayed on the liquid crystal screen 62 a after theoperation of the setting key 63 a, and therefore the pressing by mistakedoes not directly lead to a problem.

Advantageous Effect of First Embodiment

In the first embodiment, the execution key 63 b is configured to have aheight lower than other setting keys 63 a. Therefore, in order tovalidate the input of the execution key 63 b, it is necessary to pushthe execution key 63 b more deeply than other setting keys 63 a.Therefore, even if any of the user's fingers 311 touches the executionkey 63 b by mistake when the user brings the mobile terminal 301 closeto the antenna portion 261 for authentication, it is less likely tovalidate the input of the execution key 63 b which leads to amisoperation of the image forming apparatus 100.

In the first embodiment, the execution key 63 b is configured to havethe same height as or lower height than the surface of the operationpanel cover 63 c. Therefore, only a touch of any of the user's fingers311 by mistake does not cause the execution key 63 b to be depressed sodeeply as to cause the inversion of the output because the depression isobstructed by the operation panel cover 63 c, thereby decreasing thelikelihood of causing a misoperation related to the image forming actionof the image forming apparatus 100 which is caused by a validated inputof the execution key 63 b.

In the first embodiment, a first pressed surface in a non-pressed stateprotrudes more than a second pressed surface in a non-pressed state inthe opposite direction to the pressing direction. Therefore, the stopkey 251 is less likely to interfere with the mobile terminal 301 and thefingers than the keys of the numeric keypad 231 and thus is moreunlikely to be erroneously operated than the keys of the numeric keypad231.

In the first embodiment, the first pressed surface in the non-pressedstate is higher than the second pressed surface in the non-pressed statein the opposite direction to the pressing direction regarding the heightfrom the surface of the operation panel cover 63 c. For this reason, thestop key 251 is supported by the operation panel cover 63 c and is lesslikely to be operated by mistake with the mobile terminal 301 or fingersthan the keys of the numeric keypad 231.

In the first embodiment, the first pressed surface in the non-pressedstate protrudes more than the surface of the operation panel cover 63 cand the second pressed surface in the non-pressed state is recessed fromthe surface of the operation panel cover 63 c. Therefore, the stop key251 is less likely to interfere with the mobile terminal 301 and thefingers than the keys of the numeric keypad 231 and is less likely to beoperated by mistake than the keys of the numeric keypad 231.

In the first embodiment, a difference in the position in the pressingdirection between the first pressed surface in the non-pressed state andthe second pressed surface in the non-pressed state is equal to orlonger than 0.5 mm and shorter than 1 mm. Accordingly, a misoperation ofthe stop key 251 can be avoided, while a difference in the heightbetween the stop key 251 and the keys of the numeric keypad 231 isinconspicuous, thus providing an image forming apparatus excellent indesign.

Second Embodiment

FIG. 9 is a sectional view of an input operation portion according to asecond embodiment. In the first embodiment, the height of the pressedsurface is different between the keys of the numeric keypad 231 and thestop key 251. Meanwhile, in the second embodiment, a keystroke isdifferent between the keys of the numeric keypad 231 and the stop key251. The stop key 251 has a longer keystroke than the keystroke of eachkey of the numeric keypad 231, where the keystroke is a depresseddistance to the input of a signal.

As illustrated in FIG. 9, each key of the numeric keypad 231 and thestop key 251 are biased against the operation panel cover 63 c with coilsprings 68 arranged between each key of the numeric keypad 231 and theoperation board 265 and between the stop key 251 and the operation board265. Therefore, each key of the numeric keypad 231 and the stop key 251are held with a fixed gap from the tactile switch 266 mounted on theoperation board 265. If any key of the numeric keypad 231 or the stopkey 251 is pressed downward, the gap is closed and then the tactileswitch 266 is pressed by a predetermined distance. Thereby, the outputof the tactile switch 266 is inverted and the input of the key of thenumeric keypad 231 or the stop key 251 is validated.

The convex portion 231 b of any key of the numeric keypad 231 hassubstantially the same height as the convex portion 251 b of the stopkey 251. The convex portion 231 b of any key of the numeric keypad 231has the same amount of protrusion from the surface of the operationpanel cover 63 c as the convex portion 251 b of the stop key 251.

A gap 231 c between the numeric keypad 231 and the tactile switch 266 issmaller than a gap 251 c between the stop key 251 and the tactile switch266. The keys of the numeric keypad 231 each have a smaller push-inamount (keystroke) up to the height at which a key input is validatedthan the stop key 251. Therefore, the input of the stop key 251 is lesseasily validated than the input of the numeric keypad 231.

In the second embodiment, the stop key 251 has a large gap 251 c,thereby increasing the depression amount (keystroke) up to the height atwhich the operation of the stop key 251 is validated from thenon-pressed state. The keystroke from the depression of the executionkey 63 b is started until the input of the execution key 63 b isvalidated is larger than the similar keystroke of the setting key 63 a.The keystroke of the setting key 63 a, which is a moving distance of thefirst pressed surface from the non-pressed state of the setting key 63 ato an output inversion, is smaller than the keystroke of the executionkey 63 b, which is a moving distance of the second pressed surface fromthe non-pressed state of the execution key 63 b to an output inversion.

When performing authentication by bringing the mobile terminal 301 closeto the antenna portion 261, a user is able to move his/her finger awaybefore the input of the execution key is validated at the time when theuser feels a touch of the key with his/her finger, thereby preventing amisoperation of the image forming apparatus 100. Even if any of theuser's fingers 311 touches the stop key 251 by mistake when the userperforms authentication by bringing the mobile terminal 301 close to theantenna portion 261, the input of the execution key 63 b is less likelyto be validated. The stop key 251 is provided with a longer distance andtime before the validation of the key input than each key of the numerickeypad 231, thereby preventing a misoperation on the image formingapparatus 100.

Note here that, however, when the user presses the stop key 251 for thepurpose of stopping the image formation, the user intentionally deeplydepresses the stop key 251, and thus the large keystroke up to theheight at which the input of the stop key 251 is validated does not leadto a problem.

Advantageous Effect of Second Embodiment

In the second embodiment, the gap 251 c between the execution key 63 bsuch as the stop key 251 and the tactile switch 266 is large incomparison with the gap 231 c between the setting key 63 a such as anykey of the numeric keypad 231 and the tactile switch 266. Therefore, itis possible to use a common tactile switch 266 between the setting key63 a and the execution key 63 b.

A method of increasing the pressing distance (keystroke) up to theheight at which the key input on the execution key 63 b is validated,however, is not limited to the method of increasing the gap 251 c. Thekeystroke of the tactile switch 266 for the execution key 63 b may belarger than the keystroke of the tactile switch 266 for the setting key63 a. The gap 231 c and the gap 251 c may be set so as to be equal andthen the tactile switch 266 just under the execution key 63 b may be ofthe type having a larger keystroke than the tactile switch 266 justunder the setting key 63 a. In an embodiment having a start key, thekeystroke of the start key is also made larger than the keystroke ofeach key of the numeric keypad 231.

Third Embodiment

FIG. 10 is a top view of an input operation portion according to a thirdembodiment. In the first embodiment, the execution key is made lesslikely to be depressed by employing different heights between thesetting key and the execution key. On the other hand, in the thirdembodiment, a rib 63 d, which is an example of a protrusion, is providedon the surface of the input operation portion 63 adjacent to the stopkey 251 on the side where the mobile terminal 301 is brought close tothe antenna portion, so that the stop key 251 is less likely to bedepressed.

As illustrated in FIG. 10, the keys of the numeric keypad 231 each havethe same height as the stop key 251. The keystroke is also the samebetween each key of the numeric keypad 231 and the stop key 251. Thereis, however, provided the rib 63 d as a misoperation prevention wallwhich is adjacent to the stop key 251 on the operation panel cover 63 c.The rib 63 d is provided adjacent to the sides (the front side and theleft side) of the stop key 251 facing the mobile terminal 301 whichmoves toward the antenna portion 261. The rib 63 d is provided in such away as to protect two upright sides (the front side and the left side)of the stop key 251 on the antenna portion 261 side. In the embodimenthaving the start key, a rib similar to the rib 63 d is provided on thesurface of the input operation portion 63 adjacent to the start key onthe side where the mobile terminal 301 is brought close to the antennaportion.

The height of the rib 63 d is higher than at least the key height justbefore the validation of the key input caused by depressing the stop key251 from the non-pressed state. Therefore, even if the user touches thestop key 251 by mistake, the user is not able to further depress thestop key 251 because any of user's fingers 311 touches the rib 63 dbefore the input of the stop key 251 is validated. If the user moves thefinger 311 away from the rib 63 d at the time when the user feels thetouch of the rib 63 d with the finger 311, the input of the stop key 251is not validated. Even if the user depresses the stop key 251 by mistakewith any of the fingers 311 when performing authentication by bringingthe mobile terminal 301 close to the antenna portion 261, furtherdepression is prevented because any of the user's fingers 311 abutsagainst the rib 63 d before the key input is validated. This prevents amisoperation of the image forming apparatus 100 caused by a validatedinput of the stop key 251.

In the third embodiment, a user's finger touches the rib 63 d before theuser touches the execution key 63 b or, even in the case where the usertouches the execution key 63 b, before the input of the execution key 63d is validated. Therefore, the user is able to move the finger away fromthe execution key 63 b at the time when the user feels the touch of therib 63 d with the finger.

The depression itself of the stop key 251 may be prevented by increasingthe height of the rib 63 d so as to be higher than the maximum height ofthe stop key 251 in the non-pressed state. When performingauthentication by bringing the mobile terminal 301 close to the antennaportion 261, any of the user's fingers 311 abuts against the rib 63 dbefore the user's finger 311 touches the stop key 251 by mistake, bywhich the stop key 251 is not depressed. The higher the rib 63 d is, theless the depression of the stop key 251 is likely to occur. The increasein the height of the rib 63 d, however, might impair the operability ofthe stop key 251 and the design quality of the input operation portion63.

From the viewpoint of preventing a misoperation of the stop key 251, theentire periphery of the stop key 251 may be enclosed by a wall-like rib.When attempting to intentionally operate the stop key 251 for thepurpose of stopping the image formation, however, the user occasionallyfails to depress the stop key 251 because the rib lies in the way.Therefore, as illustrated in FIG. 10, it is also preferable to providethe rib 63 d only on the antenna portion 261 side of the periphery ofthe stop key 251.

The third embodiment may be combined with the first or secondembodiment. The height of the stop key 251 may be lower than the heightof each key of the numeric keypad 231 and the keystroke of the stop key251 may be larger than the keystroke of each key of the numeric keypad231.

Other Embodiments

The present invention is not limited to the specific configurationsdescribed in the first, second, and third embodiments. An embodimentgenerated by replacing some or all of the first, second, and thirdembodiments with another alternative configuration may be enabled. FIG.11 is an explanatory diagram illustrating another example of thestructure of a key switch. As illustrated in FIG. 11, the stop key 251and each key of the numeric keypad 231 may be each formed of aconductive rubber sheet 276 connected to the ground potential and aswitch contact 277 provided on a switch board 278.

The communication components can be implemented by various types ofdevices that can be authenticated by wireless communication, such as adigital camera, a video camera, a mobile phone, a smartphone, a tabletterminal, a wireless communication unit, a personal digital assistant(PDA), a remote-control unit, and the like. The authentication mediummay be implemented by a card medium not having a power supply using anIC tag.

Although the embodiments in the electrophotographic image formingapparatus 100 have been described in the first, second, and thirdembodiments, the image forming portion capable of forming an image on arecording medium is not limited to one in the electrophotographic imageforming apparatus. Even an image forming apparatus using anotherrecording system or printing system such as an inkjet recording systemcan implement the present invention.

Since the embodiments of a printer are described in the first, second,and third embodiments, the execution key 63 b is only the stop key 251.The present invention, however, can be implemented by a complex machinehaving a copier, a facsimile machine, and a scanner function. In thatcase, the start key may be located next to the stop key 251 in thevicinity thereof (for example, to the left), though the start key isdisplayed on the liquid crystal screen 62 a in the first, second, andthird embodiments. In that case, two keys, namely the added start keyand the stop key 251 are execution keys 63 b.

In the first, second, and third embodiments, the operation portion 61 isvertically long and therefore there are arranged the liquid crystalscreen 62 a which is a display portion, the input operation portion 63,and the antenna portion 261, which performs authentication, in sequencefrom the rear side. The operation portion 61, however, may behorizontally long. In this case, from the viewpoint of humanengineering, it is preferable to arrange the liquid crystal screen 62 a,the input operation portion 63, and the antenna portion 261 in orderthereof from the left. Also in this case, the execution key 63 b isarranged nearest to the antenna portion 261 in the same manner.

The first, second, and third embodiments may be singly implemented ortwo or three of the embodiments may be implemented in combination. Forexample, it is possible to use an embodiment in which a small differencein the amount of protrusion, a small difference in the keystroke, and arib having a low height are used at a time, with respect to theexecution key 63 b and the setting key 63 a.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2015-140518, filed Jul. 14, 2015, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. An image forming apparatus comprising: an imageforming portion capable of forming an image on a recording medium; anoperation portion for performing an operation of the image formingapparatus; a push button which is arranged in a surface of the operationportion, and with which a signal of stopping an image forming actionperformed by the image forming portion is input; a receiving portionprovided in the operation portion so as to be able to receive a radiosignal from a communication component by placing the communicationcomponent transmitting the radio signal so as to face the receivingportion; and at least a central portion of the push button located at aposition recessed from the surface of the operation portion.
 2. Theimage forming apparatus according to claim 1, comprising: the pushbutton which is a first push button; and a second push button which isarranged in the surface of the operation portion, and with whichinformation relating to numerals is input, wherein a central portion ofthe second push button is higher than the central portion of the firstpush button in a direction of protruding from the surface of theoperation portion.
 3. The image forming apparatus according to claim 2,wherein the central portion of the second push button is located at aposition protruding more than the surface of the operation portion. 4.The image forming apparatus according to claim 2, wherein a depresseddistance to a switch for inputting a signal of the first push button islarger than a depressed distance to a switch for inputting a signal ofthe second push button.
 5. The image forming apparatus according toclaim 1, wherein the receiving portion is provided on the nearer side onthe image forming apparatus than the push button.
 6. The image formingapparatus according to claim 1, wherein a portion around the centralportion of the push button protrudes more than the central portion andthe protruding portion is located at a position flush with or recessedfrom the surface of the operation portion.
 7. The image formingapparatus according to claim 1, further comprising a push button forturning on or off a power supply of the image forming apparatus.
 8. Animage forming apparatus comprising: an image forming portion capable offorming an image on a recording medium; an operation portion forperforming an operation of the image forming apparatus; a push buttonwhich is arranged in a surface of the operation portion, and with whicha signal of starting an image forming action performed by the imageforming portion is input; a receiving portion provided in the operationportion so as to be able to receive a radio signal from a communicationcomponent by placing the communication component transmitting the radiosignal so as to face the receiving portion; and at least a centralportion of the push button located at a position recessed from thesurface of the operation portion.
 9. The image forming apparatusaccording to claim 8, comprising: the push button which is a first pushbutton; and a second push button which is arranged in the surface of theoperation portion, and with which information relating to numerals isinput, wherein a central portion of the second push button is higherthan the central portion of the first push button in a direction ofprotruding from the surface of the operation portion.
 10. The imageforming apparatus according to claim 9, wherein the central portion ofthe second push button is located at a position protruding more than thesurface of the operation portion.
 11. The image forming apparatusaccording to claim 9, wherein a depressed distance to a switch forinputting a signal of the first push button is larger than a depresseddistance to a switch for inputting a signal of the second push button.12. The image forming apparatus according to claim 8, wherein thereceiving portion is provided on the nearer side on the image formingapparatus than the push button.
 13. The image forming apparatusaccording to claim 8, wherein a portion around the central portion ofthe push button protrudes more than the central portion and theprotruding portion is located at a position flush with or recessed fromthe surface of the operation portion.
 14. The image forming apparatusaccording to claim 8, further comprising a push button for turning on oroff a power supply of the image forming apparatus.